The disclosures herein relate generally to computer systems and more particularly to an apparatus and method for mounting a heat generating component in a computer system.
Heat dissipating devices are commonly used to aid in dissipating heat from heat generating components in electronic devices such as computers. Heat dissipating devices are configured to readily dissipate heat from one or more heat generating components to the surrounding atmosphere or to an attached cooling component. To provide for acceptable and efficient heat transfer, a heat extraction body of the heat dissipating device must be in sufficient contact with the heat generating component.
Current methods of attaching a heat extraction body to a surface of a heat generating component includes the use of coil springs. The springs are compressed to develop a force for engaging the heat extraction body against the heat generating component. The shortcomings of this technique include numerous loose parts to assemble. Typically, as many as four coil springs and four screws are used to fasten the heat extraction body to the heat generating component. This technique also requires that an assembly torque specification for the fasteners be followed to ensure that the proper force is applied to the heat extraction body. There is also a possibility of the need for special assembly instructions specifying a specific tightening order for the fasteners to prevent binding.
Improved system components for electronic devices such as computers are rapidly and continuously being introduced in the market. In the case of a central processing unit (microprocessor) of a computer, the operating speeds are continually increasing. Because the microprocessor largely dictates the performance of a given computer, it is desirable to immediately incorporate the latest microprocessor offering into the manufacture of computer systems at the most economical manufactured cost. This practice effectively controls the inventory of computers with non-current microprocessor technology.
Several manufacturing strategies may be employed to accommodate frequent revisions to the microprocessor in the manufacture of a particular computer or line of computers. To speed delivery and minimize inventory of motherboards having non-current microprocessor technology, microprocessors may be purchased directly from the supplier and installed on the motherboard at the computer manufacturing facility. This often necessitates buying the microprocessor in a bare chip format (no integral heat spreader plate) rather than as a packaged microprocessor module. To enable the microprocessor to be attached to the motherboard at the computer manufacturing facility, the motherboard includes a socket for receiving the microprocessor rather than the microprocessor being soldered directly to the motherboard.
U.S. Pat. No. 5,977,623 discloses a semiconductor package including a socket that is adaptable to a multiple pin structure. The package includes a nonconductive base layer, a plurality of conductive metallic leads that extend vertically through the base layer and a wiring layer in which a pattern of fine metallic wires are formed to electrically couple the conductive metallic leads to a semiconductor chip mounted in the socket. A recess is formed in the central portion of the wiring layer and a cover for closing the upper portion of the recess is attached to the socket. A semiconductor device is mountable on the bottom portion of the recess and conductive wires electrically couple the semiconductor chip to the fine metallic wires of the wiring layer. The socket includes a socket body having a hinged cover. A first plurality of socket pins are arranged to couple with leads on a bottom surface of a semiconductor chip package mounted in the socket. A second plurality of socket pins are arranged to couple with leads on peripheral side surfaces of a semiconductor chip package mounted in the socket. The cover may include an integral heat sink portion.
U.S. Pat. No. 5,923,179 discloses a test socket used to test an integrated circuit that is mounted on a package or circuit board. The test socket includes a base that supports the integrated circuit and the circuit board. Pivotally connected to the base of the socket are a pair of heat sinks that can be moved between a first position and a second position. When in the first position, the heat sinks are pressed into contact with a semiconductor of either the package or integrated circuit to provide a direct conductive path between the integrated circuit die and the heat sinks. A plurality of test contacts are placed into contact with a plurality of surface pads located on the package to test the package or integrated circuit. The direct conductive path between the heat sinks and the semiconductor device lowers the overall thermal impedance of the socket assembly and the junction temperatures of the integrated circuit during an electrical test routine.
U.S. Pat. No. 5,409,392 discloses a socket for carrying an integrated circuit (IC) package. The socket, which is particularly useful for burn-in testing, includes a base which houses a plurality of conductive contacts and a movable top pivotally connected to the base. A table is connected to the base and supports the IC package after insertion. The socket also includes a contact actuation plate which is operably connected to the movable top and is pivotal with the top. Latches are movably connected to the base and shift with the top between latched and unlatched positions to secure the IC atop the table during testing. The actuator plate may also include retractable locator pins to insure proper IC alignment in the socket.
Microprocessor modules without an integral heat spreading plate can pose a unique challenge for mounting a heat dissipating device thereon. To provide optimum heat transfer, it is preferred for the heat extraction body to be brought into direct contact with the microprocessor chip with a nominal amount of contact pressure applied uniformly over the area of the microprocessor chip. A tolerance build-up associated with the socket, the microprocessor and the heat extraction body often complicate the attachment of the heat dissipating device to the heat generating component. Insufficient contact pressure between the heat extraction body and the heat generating component reduces thermal efficiency. Excessive pressure can distort the heat extraction body, reducing the level of heat transfer. Furthermore, excessive pressure can also damage to the microprocessor chip or motherboard due to stress concentrations. Therefore, what is needed is an apparatus for mounting a heat generating component and a heat dissipating device on a printed circuit substrate that economically and reliably compensates for tolerance build-up.
Accordingly, in one embodiment, a heat generating component is mounted on a base member using a free-floating heat extraction body and resilient members mounted on a retaining member to compensate for dimensional tolerances. To this end, an apparatus for removing heat from a computer component includes a base member having a frame member mounted thereon. The frame defines an opening therein for receiving a heat generating computer component. A heat extraction body is adjacent the opening for being mounted on the heat generating component. A retaining member is mounted adjacent the frame for movement into engagement with the heat extraction body. A resilient interconnection is provided between the retaining member and the heat extraction body for urging the heat extraction body into engagement with the heat generating component.
A principal advantage of this embodiment is that mechanical tolerances of the heat extraction body and the heat generating component are compensated for by captive, self-adjusting mounting hardware such that tolerance variability does not adversely affect heat transfer performance.